Insulation cutter



July 17, 1951v J. F. coAsTELow 2,561,099

' INSULATION CUTTER Filed Jan. 15, 1947 IN VEN TOR.' A .Jam 00s eZow,

Y 1MM Patented uly 17, 1951 f INSULATION GUTTER John F Costelow, KansasCtyQMo.

yApplication* January 15, 1947,?Serial No. 722,121

(clito-91) My invention relates to.'devices forl cutting linsulatingsheaths or coverings of cableslong'ituv"-:dinally at theire'nds, so thataccess Imaybehad `to thefenclose'd conductors, for*the*p'urposefof'connecting thefends thereof tofvarious electrical instruments r 'forsplicing4 them tof the endsof y 'other conductors.

` My device iscapable-of=eut`ting' sheaths ofdifferent thicknesses fanddiameters y"made from V"variouskinds ofnaterial, such, for'example, asabrics, lead, or rubber.

The present invention is an improvement lon the insulationcutterdisclos'ed'by my copending `fzalpplication, lSerialtNo."624`,'82`0,` "led' October "26, 1945, vnow PatentNo. '22452,734,issuedfNoVember 2, 1948. Objects of the'y instant inventionlv aretoAimprove and' reduce the number 'ofi-'parts' entering-into vtheconstructionofthe device by `com- -"bining the: frame and. handlethereof'in 'al single -1 streamlined casting'and 'dispensingLI with av-num- `lberof other parts, to enclose mo'st'of'theworking Aparts in theframe-'of the'- device" where'theywill 'fbel protected'fromdamage'due tothe rough 'usage 'towhich tools fv this 'characteraresubjected to'provide a blade with a ldullf-end thatcan be forced into afsheathto'thefenclosed 'individual *conductors withoutcuttingthe respectiveinsula- Itioncoverings of the latter, means for adjusting 'fthe blade to"accommodate cables vof different diameters, and' to provide I`a'sat''which can'be iadjusted to support cables of"variousfsizes,one at'a' time, whileA being actedupon'b'y'the'blade.

'fther objects will hereinafter `appear' fand `in "order vthat theinvention may j Abe `ful1y`under "stood," reference will now beiliadtothexaccomfpanying drawing, in which: v I

lFigt 1`is' ajside elevation of the-devicejwith LApart of a cablevlocated therein and-partly k'slit "'near one'end by the blade.

isa brokenftop'plan view of the'device. nFig. 3 vis abrokenlongitridinaltsection 'on line TE3--3 of Fig. 2, Ywitirtheadditionofpart ff'a r"cable, y

Fig-f 4 isla cross" section on' line 4 14 fir'igf'z,

""vvith'theadditionof a cable' in cross' section.`

"ing, one at atime,cables-of'differentdiameters AIn order to avoidconfusion in the following '-ds'crption and vclaims asto the lposition'and direction o'f l niovement'of'paits, it )will be! assumed '.give thedevice a streamline appearance.

vthat-the device vis-disposed in-a horizontalposiitionas-disclosedbyFig. 1.

In carrying loutthe invention I providea frame Zf'withan integralhandlel, having `a longitudi- :nal groove 6, registering at its forwardend with a bore' 8, extending longitudinally through the lower portionofthe frame 2 and which cooperates 'with the `groove'I in guiding andsupporting an insulated cable such, for example, as thefcablefA,

covered by -van insulatingl sheath B enclosing a pluralityofwireconductorsfC, with individual ycoverings'of insulation D. Thesides ofthe frame 2 andthe handle Ailffare preferablyV flush with each'otherand' the front and rear edges ofthe frames taper upwardlyl as'disclosed-by Fig. 1, to The frame-2 includes a pair of vspaced'sidewalls I0 r giris of the side walls I0 to opposite'sides of ya I2 whichextend vdownward-'from the -upper `marrecess I4 formed in the lowerportion of the 'framefand communicating with 'the bore 8.

The arms I8 are providedat theirupper The set screws 22 toclampthelouter-"surface of the arms I8 and thus firmly hold theU-member I6 :atany4 point of'its vertica'adjustme'nt. Preferably the'slots 520 havelopen-'upper ends 'as shown, to permit 'necessitating'removal*of' thesetscrews 22 from thefsidewalls- IIJ. The .U-member `I6 is'provided atitslower-i-nner'porftion with a VV-seat 24-"for *supporting-cables ofdiierent diameters, one'at va time. each ycable-placed therefrom fromv'shifting laterally-while ta blade 26 fisibeing forced downtoi"penetrate the upper thicknessof the sheath.

removal fof4 the 4U-'me'mber I6v ifdesired, Without TheVV-seat -24 isadapted to prevent Thefibladel26-is1secured to a blade" holderf 30 Abysuitable A.means "such, for instance, asf screws *'32. 4'Ihe'f-blade hastwo Icutting or sharp'dgs 33; tapering downward tota dull orblunt--end38 insulation ywhile y; the V`blunt vvend 'f 38 pushes `-the innerconductors Cdown'ward and away from the "cuttin'g'edges33 The' bluntend'38 also-performs the foregoing Voperation d uring slitting f `ofy'the insulation longitudinally, thereby --avoiding *the necessity ofusing the fingers of the worker to pull the sides of the slit portionapart to observe the condition of the insulation on the conductors C.Thus danger of cutting the nger on the sharp edges 33 is avoided and thetime and labor heretofore required in frequent inspections of theconductors C during slitting of the outer insulation B is saved. A slot34 extending through the upper wall 36 of the bore 8 permits the blade26 to enter said bore and act on the insulation B f the cable.

The blade 26 is actuated by a hand lever 40 extending forwardly betweenthe spaced walls l0 and mounted at its forward end upona Apivot 42extending transversely through axially alined holes in the walls I8. Thehand lever 40 is provided at its forward portion with a loop 44, Fig, 2,to receive the lower part of the blade holder 38 which is connected by apivot 48 to opposite sides of the loop 44, Fig, 4. The blade holder 30operatesbetweenthe spaced walls I0 and is provided at its upper portionwith shoulders 48, projecting in wardly from the blade holder 38 andprovided with a rotatable member 54 bearing on'top of the side walls l0of the frame 2 and adapted when rotated in one direction to force thethreaded member 52 and blade holder 3D downward, or lift them when therotatable member 52 is turned in a reverse direction. AV coiled spring56, surrounding the threaded member 52 and interposed between the bladeholder 30 and rotatable member 54, exerts suicient pressure on thelatter to p-revent accidental rotation thereof. A scale 58 on one sideof the frame 2 and an index 60 on the adjacent arm I8 are provided toassist the operator in locating the lower end 38 of the blade 26 withrespect to the cable resting upon the underlying seat 24, so thatdownward movement of the blade may be checked on penetration of theupper thickness of the sheath.

In practice, a cable such as A, may be inserted in the bore 8, througheither end of the latter, Assuming that the cable is inserted throughthe left end of the bore, it is pushed inward past the seat 24 and theblade 26 a distance equal tothe length of the slot which it is desiredto cut in the sheath B. The hand lever 48 is then pushed downward toforce the dull terminal 38 of the blade 26 through the upper thicknessof the sheath B and against one of the upper conductors C or between twoupper conductors. Downward movement of the lever 40 is then checked bythe rotatable member 54 contacting the top of the frame 2. The handle 4is then firmly grasped with one hand and the cable A is grasped with theother hand and pulled from the left end of the bore 8, therebycompleting the slit D, partly completed as shown by Fig. 3.

From the foregoing description taken in connection with the accompanyingdrawing, it will be understood that one improvement of the presentinvention resides in combining the frame 2 and the handle 4 in onestreamlined member with alined groove 8 and bore 8, instead of twomembers which are separately produced and assembled for use. Theadjustable U-member I8 with seat 24 also constitutes other improvementsas they may be adjusted vertically relative to the upper wall 36 of thebore 8, to accommodate cables of different diameters and thus dispensewith the use of tubular inserts of various diameters. Other improvementsreside in the blade holder 38 and double cutting edged blade 26 with thedull terminal 38, to avoid cutting the insulation on the innerconductors C. A further improvement resides in the loop 44 ofthe lever48 and pivotally f connecting the blade holder 48 thereto, thusdispensing with link connections and forked ends of the former locatedon the outside of the frame where they were liable to damage.

While I have illustrated and described a pre- -ferred form of my device,I reserve all rights to such changes and modifications thereof asproperly fall within the scope of the invention as claimed.

Having thus described my invention, what I claim and desire to secure byLetters Patent, is:

1. An insulation cutter comprising a frame with a bore extendinglongitudinally therethrough, a blade adjustably mounted in lthe frame, ablade holder adjustably mounted` in the frame and to which the blade issecured', a lever extending into an opening in the frame and providedwith a loop throughwhich the blade holder extends, and independent meanspivotally connecting the lever to the frame and the blade holder wherebythe latter and the blade may be adjusted relative to an insulated cableinserted in the bore.

2. An insulation cutter comprising a frame with a bore extendinglongitudinally therethrough, a blade `adjustably mounted in the frame, ablade holder adjustably mounted in the frame and to which the blade issecured, a lever extending into an opening in the frame and providedwith a loop through which the blade holder extends, independent meanspivotally connecting the lever to the frame and the blade holder wherebythe latter andY the blade maya-be quickly adjusted relative to the bore,and means associated with the frame and the blade holder formicrometrically adjusting the blade holder and the blade relative to thepassageway. v

3. An insulation cutter comprising a frame including two spaced sidewalls and a longitudinal bore, a blade in the frame, a blade holdercarrying the blade and slidably mounted in confronting grooves in theside walls, a hand lever ex.- tending between thek spaced walls of theframe, a transverse member secured in the spaced walls and upon whichthe hand lever is operably mounted, a loop on the handlever throughwhich the blade holder freely extends, and pivotal means connecting theblade holder to theloop for movement of the blade holder and the bladerelative to the frame and to an insulated cable inserted in the bore andadapted to vbe grasped and withdrawn from the bore and thereby slit theinsulation.

4. An insulation cutter comprising a frame including two spaced sidewalls and a longitudinal bore, a blade in the frame, a blade holdercarrying the blade and slidably mounted in confronting grooves in theside walls, a hand lever extending between the spaced Walls of theframe, a transverse member secured in the spaced Walls and upon Whichthe hand lever is operably mounted, pivotal means connecting the blade'.holder to the hand lever whereby rapid adjustment of 5 A the bladeholder and the blade relative to the bore may be had, and micrometeradjusting means whereby ne adjustment of the blade holder and the bladerelative to the bore may be had, said micrometer adjusting meanscomprising a member threaded into the blade holder, a rotatable membermounted upon said threaded member and bearing upon the spaced walls, andan expansible spring encircling the threaded member and interposedbetween the blade holder and said rotatable member.

5. In an insulation cutter comprising a frame having two spaced sidewalls united by a bottom portion of the frame, said bottom portionhaving a bore extending longitudinally therethrough and a recesscommunicating with the bore, a U- member having a pair of spaced armsvertically slidable on the spaced side walls of the frame and its lowerportion movably arranged in the recess, adjustable means for securingthe U- member to the frame at any point of its vertical movement, ablade in the frame adapted to project through a slot in the lowerportion of the frame and which communicates with the bore at a pointabove the bottom of the U-member, and means in the frame for adjustingthe blade vertically relative to an insulated cable inserted in the boreand resting upon the bottom of the U-member, said cable being adapted tobe grasped and withdrawn from the bore, thereby slitting the insulationon the cable.

6. In an insulation cutter comprising a frame having two spaced sidewalls united by a bottom portion of the frame, said side walls havinggrooves extending downward from their upper margins to opposite uppermargins of the recess, said bottom portion havinga bore extendinglongitudinally therethrough and a recess communicating with the bore, aU-member slidable in the grooves and the recess and provided in itslower portion with a seat, adjustable means for securing the U-member tothe frame at any point of its vertical movement, a blade in the frameadapted to project through a slot in the lower portion of the frame andwhich communicates with the bore at a point labove the seat in theU-member, and means inthe frame for adjusting the blade verticallyrelative to an insulated cable inserted in the bore and resting upon thebottom of the U-member, said cable being adapted to be grasped andWithdrawn from the bore, thereby slitting the insulation on the cable.

JOHN F. COSTELOW.

REFERENCES CITED The following references are of record in the 111e ofthis patent:

UNITED STATES PATENTS Number Name Date 2,353 Demetropoulos July 1l, 19441,692,030 Friedman Nov. 20, 1928 2,385,368 Montgomery Sept. 25, 19452,452,734 Costelow Nov. 2, 1948 FOREIGN PATENTS Number Country Date555,099 Great Britain July 29, 1943

